{"id":"CVE-2026-31434","state":"PUBLISHED","title":"btrfs: fix leak of kobject name for sub-group space_info","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix leak of kobject name for sub-group space_info\n\nWhen create_space_info_sub_group() allocates elements of\nspace_info->sub_group[], kobject_init_and_add() is called for each\nelement via btrfs_sysfs_add_space_info_type(). However, when\ncheck_removing_space_info() frees these elements, it does not call\nbtrfs_sysfs_remove_space_info() on them. As a result, kobject_put() is\nnot called and the associated kobj->name objects are leaked.\n\nThis memory leak is reproduced by running the blktests test case\nzbd/009 on kernels built with CONFIG_DEBUG_KMEMLEAK. The kmemleak\nfeature reports the following error:\n\nunreferenced object 0xffff888112877d40 (size 16):\n  comm \"mount\", pid 1244, jiffies 4294996972\n  hex dump (first 16 bytes):\n    64 61 74 61 2d 72 65 6c 6f 63 00 c4 c6 a7 cb 7f  data-reloc......\n  backtrace (crc 53ffde4d):\n    __kmalloc_node_track_caller_noprof+0x619/0x870\n    kstrdup+0x42/0xc0\n    kobject_set_name_vargs+0x44/0x110\n    kobject_init_and_add+0xcf/0x150\n    btrfs_sysfs_add_space_info_type+0xfc/0x210 [btrfs]\n    create_space_info_sub_group.constprop.0+0xfb/0x1b0 [btrfs]\n    create_space_info+0x211/0x320 [btrfs]\n    btrfs_init_space_info+0x15a/0x1b0 [btrfs]\n    open_ctree+0x33c7/0x4a50 [btrfs]\n    btrfs_get_tree.cold+0x9f/0x1ee [btrfs]\n    vfs_get_tree+0x87/0x2f0\n    vfs_cmd_create+0xbd/0x280\n    __do_sys_fsconfig+0x3df/0x990\n    do_syscall_64+0x136/0x1540\n    entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nTo avoid the leak, call btrfs_sysfs_remove_space_info() instead of\nkfree() for the elements.","publishedAt":"2026-04-22T13:53:34.357Z","updatedAt":"2026-05-23T16:05:03.539Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"64c7ddda83acfbaa0efb381a1928ce908c584607","status":"affected","lessThan":"416484f21a9d1280cf6daa7ebc10c79b59c46e48","versionType":"git"},{"version":"0bd151ce4200ca847990e05cca29a76456982ca5","status":"affected","lessThan":"94054ffd311a1f76b7093ba8ebf50bdb0d28337c","versionType":"git"},{"version":"190d5a7c4fe42b8c9aa46e3336389e7cb10395bb","status":"affected","lessThan":"1737ddeafbb1304f41ec2eede4f7366082e7c96a","versionType":"git"},{"version":"f92ee31e031c7819126d2febdda0c3e91f5d2eb9","status":"affected","lessThan":"3c844d01f9874a43004c82970d8da94f9aba8949","versionType":"git"},{"version":"f92ee31e031c7819126d2febdda0c3e91f5d2eb9","status":"affected","lessThan":"3c645c6f7e5470debbb81666b230056de48f36dc","versionType":"git"},{"version":"f92ee31e031c7819126d2febdda0c3e91f5d2eb9","status":"affected","lessThan":"a4376d9a5d4c9610e69def3fc0b32c86a7ab7a41","versionType":"git"},{"version":"6.1.162","status":"affected","lessThan":"6.1.168","versionType":"semver"},{"version":"6.6.122","status":"affected","lessThan":"6.6.131","versionType":"semver"},{"version":"6.12.67","status":"affected","lessThan":"6.12.80","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/block-group.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.131","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.80","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.21","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.11","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/block-group.c"]}],"references":["https://git.kernel.org/stable/c/416484f21a9d1280cf6daa7ebc10c79b59c46e48","https://git.kernel.org/stable/c/94054ffd311a1f76b7093ba8ebf50bdb0d28337c","https://git.kernel.org/stable/c/1737ddeafbb1304f41ec2eede4f7366082e7c96a","https://git.kernel.org/stable/c/3c844d01f9874a43004c82970d8da94f9aba8949","https://git.kernel.org/stable/c/3c645c6f7e5470debbb81666b230056de48f36dc","https://git.kernel.org/stable/c/a4376d9a5d4c9610e69def3fc0b32c86a7ab7a41"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31434.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31434","state":"PUBLISHED","datePublished":"2026-04-22T13:53:34.357Z","dateUpdated":"2026-05-23T16:05:03.539Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.089Z"},"containers":{"cna":{"title":"btrfs: fix leak of kobject name for sub-group space_info","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix leak of kobject name for sub-group space_info\n\nWhen create_space_info_sub_group() allocates elements of\nspace_info->sub_group[], kobject_init_and_add() is called for each\nelement via btrfs_sysfs_add_space_info_type(). However, when\ncheck_removing_space_info() frees these elements, it does not call\nbtrfs_sysfs_remove_space_info() on them. As a result, kobject_put() is\nnot called and the associated kobj->name objects are leaked.\n\nThis memory leak is reproduced by running the blktests test case\nzbd/009 on kernels built with CONFIG_DEBUG_KMEMLEAK. The kmemleak\nfeature reports the following error:\n\nunreferenced object 0xffff888112877d40 (size 16):\n  comm \"mount\", pid 1244, jiffies 4294996972\n  hex dump (first 16 bytes):\n    64 61 74 61 2d 72 65 6c 6f 63 00 c4 c6 a7 cb 7f  data-reloc......\n  backtrace (crc 53ffde4d):\n    __kmalloc_node_track_caller_noprof+0x619/0x870\n    kstrdup+0x42/0xc0\n    kobject_set_name_vargs+0x44/0x110\n    kobject_init_and_add+0xcf/0x150\n    btrfs_sysfs_add_space_info_type+0xfc/0x210 [btrfs]\n    create_space_info_sub_group.constprop.0+0xfb/0x1b0 [btrfs]\n    create_space_info+0x211/0x320 [btrfs]\n    btrfs_init_space_info+0x15a/0x1b0 [btrfs]\n    open_ctree+0x33c7/0x4a50 [btrfs]\n    btrfs_get_tree.cold+0x9f/0x1ee [btrfs]\n    vfs_get_tree+0x87/0x2f0\n    vfs_cmd_create+0xbd/0x280\n    __do_sys_fsconfig+0x3df/0x990\n    do_syscall_64+0x136/0x1540\n    entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nTo avoid the leak, call btrfs_sysfs_remove_space_info() instead of\nkfree() for the elements."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"64c7ddda83acfbaa0efb381a1928ce908c584607","status":"affected","lessThan":"416484f21a9d1280cf6daa7ebc10c79b59c46e48","versionType":"git"},{"version":"0bd151ce4200ca847990e05cca29a76456982ca5","status":"affected","lessThan":"94054ffd311a1f76b7093ba8ebf50bdb0d28337c","versionType":"git"},{"version":"190d5a7c4fe42b8c9aa46e3336389e7cb10395bb","status":"affected","lessThan":"1737ddeafbb1304f41ec2eede4f7366082e7c96a","versionType":"git"},{"version":"f92ee31e031c7819126d2febdda0c3e91f5d2eb9","status":"affected","lessThan":"3c844d01f9874a43004c82970d8da94f9aba8949","versionType":"git"},{"version":"f92ee31e031c7819126d2febdda0c3e91f5d2eb9","status":"affected","lessThan":"3c645c6f7e5470debbb81666b230056de48f36dc","versionType":"git"},{"version":"f92ee31e031c7819126d2febdda0c3e91f5d2eb9","status":"affected","lessThan":"a4376d9a5d4c9610e69def3fc0b32c86a7ab7a41","versionType":"git"},{"version":"6.1.162","status":"affected","lessThan":"6.1.168","versionType":"semver"},{"version":"6.6.122","status":"affected","lessThan":"6.6.131","versionType":"semver"},{"version":"6.12.67","status":"affected","lessThan":"6.12.80","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/block-group.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.131","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.80","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.21","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.11","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/btrfs/block-group.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/416484f21a9d1280cf6daa7ebc10c79b59c46e48"},{"url":"https://git.kernel.org/stable/c/94054ffd311a1f76b7093ba8ebf50bdb0d28337c"},{"url":"https://git.kernel.org/stable/c/1737ddeafbb1304f41ec2eede4f7366082e7c96a"},{"url":"https://git.kernel.org/stable/c/3c844d01f9874a43004c82970d8da94f9aba8949"},{"url":"https://git.kernel.org/stable/c/3c645c6f7e5470debbb81666b230056de48f36dc"},{"url":"https://git.kernel.org/stable/c/a4376d9a5d4c9610e69def3fc0b32c86a7ab7a41"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T16:05:03.539Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.162","versionEndExcluding":"6.1.168"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.122","versionEndExcluding":"6.6.131"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.67","versionEndExcluding":"6.12.80"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.21"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.19.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}